As used herein, the term "card" refers to any type of credit card or credit account mechanism including, but not limited to: a) a telephone-company-issued card, such as the Bell Atlantic IQ Card, b) a combined commercial credit card and telephone card, such as the AT&T Universal Card, c) a commercial credit card, such as American Express, or d) a debit card. A "card number" is a multi-character string that identifies the account associated with a card. A "card call" is a telephone call whose cost is charged to the account associated with a card. Other ways of saying this are that the call is charged to the card or the call is charged to the card number. It will be appreciated that card issuers, i.e., the providers of the credit for each card, need not provide a tangible manifestation, such as embossed plastic, for each card.
It should be recognized that wherever the particular identifying mechanism of a personal identification number (PIN) is called for herein, there is no intention to exclude use of other personal identifying mechanisms such as voice prints, finger prints, retina patterns, etc. PIN is used simply because it is commonly used today in the making of card calls and, therefore, its use should aid in understanding the invention. It is noted that, depending on one's perspective, the characters comprising a PIN may or may not be considered as an integral part of the card number.
It should also be recognized that a telephone station, when called for herein, indicates both a) the typical case where a single telephone station set is connected to a single telephone line of a central office or to a single station port of a private branch exchange (PBX) and b) the situation in which two or more telephone station sets are connected in parallel with each other on a single telephone line of a central office or a single station port of a PBX. This is because, typically, the central office or PBX cannot distinguish between such bridged telephone stations sets nor even recognize that there is more than one.
Currently, as a general rule, a caller who places a call to be charged to a card must enter all of the digits of his card number and the associated PIN, if any, for each such call. This is cumbersome and time consuming. The process of placing calls charged to cards may also be further encumbered by requiring the caller to dial special codes to obtain access to a local exchange and, if necessary, an interexchange access code to connect the caller to his interexchange carrier of choice. Such additional codes are typically necessary when calling from a hotel or hospital room, from which calls charged to cards are often made.
Exceptions to this general rule exist, but they are very limited. Specifically, with sequence calling, a caller places several calls in a row that are each charged to the card. The card number is entered only for the first call, the calls in the sequence being either all intra-lata or all inter-lata calls, and the end of each preceding call and the beginning of the next call being signaled only by the caller pressing a delimiter associated with sequence calling, such as the pound key (#), rather than going on hook. Sequence calling does not work once the calling telephone has gone on hook. Also, some systems offer a form of abbreviated card entry, when the called number is a subset of the card number, e.g., calling a home number using a line-based calling card associated with the home number, for which only the PIN, and not the entire card number, need be entered.